1. LISA Update Bernard Schutz Albert Einstein Institute, Potsdam, Germany and Cardiff University, Wales GWDAW-10, Brownsville, 14 December 2005

2. LISA Current progress on LISA  LISA in Formulation Phase study (Astrium, Germany)  LISA Pathfinder on track for launch 2009  LIST re-formed this year, sharpening science goals  Strong focus on developing data analysis for LISA  Recent technology review at Goddard  Strong competition for funds and priority in both NASA and ESA  Science from LISA

3. LISA Hardware development  Astrium (Germany) study of LISA supports Formulation Phase activities (old Phase A and B).  Design down to components, mass budgets, power budgets, data telemetry requirements.  Trade-off studies for reducing costs, increasing reliability  LISA Pathfinder (LPF: ESA mission), launch 2009, will carry LTP (European sensor) and two systems of thrusters and controls (from US and Europe).  LPF nearing end of Phase B, engineering models of all components being qualified for launch.  LPF tests completely all the LISA metrology, which is the most challenging aspect of LISA. Ensures that LISA technology is at a state of readiness for a 2009 mission, much earlier than target launch date 2013.

4. LISA New LISA International Science Team  NASA membership  T Prince (co-chair)  P Bender  S Buchman  J Centrella  N Cornish  S Finn  W Folkner  J Gundlach  C Hogan  S Hughes  P Madau  S Phinney  D Richstone  K Thorne  Serve from 01/2005 for two years.  LIST meets twice/year, operates Working Groups and Task Forces  Meetings open  LIST guides project development, design  Sets scientific priorities – Compact binaries and merging black holes are highest priority goals – EMRIs and backgrounds are next priority level  Guides development of data analysis system  ESA membership  K Danzmann (co-chair)  P Binetruy  M Cerdonio  M Cruise  C Cutler  J Hough  P Jetzer  Y Mellier  B Schutz  T Sumner  J-Y Vinet  S Vitale LIST website http://www.srl.caltech.edu/lisa/http://www.srl.caltech.edu/lisa/

5. LISA Data analysis  General recognition that LISA data analysis is challenging – Confusion of sources, problem not faced by ground-based projects – Low-frequency, long-duration sources  ESA and NASA are organizing communities – JPL (Tom Prince) is NASA focus, had workshop 13-15 October (http://www.tapir.caltech.edu/dokuwiki/workshop:start)http://www.tapir.caltech.edu/dokuwiki/workshop:start – ESTEC (Oliver Jennrich) is ESA focus, had workshop 31 October. Issued invitation to submit letter of intent: over 45 institutions, with 250 scientists, responded. – Overall coordination provided by LIST Data Analysis Working Group (DAWG), co-chaired by N Cornish and B Schutz  Immediate goals – Developing infrastructure (LISA data generators, standards, etc) – Developing working, effective algorithms – Tool: mock data challenges  Longer-term goal (by 2009?) – Delivery of architecture design, hand-over to professional programmers

6. LISA Current issues  Both NASA and ESA have funding constraints.  Strong pressure from other missions waiting in queue, especially after failure of recent Japanese X-ray mission.  GSFC recently reviewed technology readiness of LISA and Con- X. Waiting for report.  NASA top-level management changes create uncertainty on priorities. However, no changes in priorities have been made or even suggested.  ESA preparing to make a decision early next year on dropping one existing mission from portfolio in order to cope with cost overruns. LISA is one candidate.  Important at this point to emphasize LISA’s extremely strong science case!

7. LISA LISA Science - 1  LISA has both fundamental physics and astrophysics goals.  Fundamental physics: – Tests of relativistic gravity using mergers of comparable-mass BHs: –strong-gravity aspects (comparison with numerical relativity simulations) –Hawking area theorem (before and after measurements of M and J) –cosmic censorship hypothesis (is a/M > 1 after merger?) – Test uniqueness of Kerr (no hair theorem) by observing detailed waveforms from Extreme Mass-Ratio Inspiral events (EMRI’s) – Observe low-frequency GWs for first time and validate weak-field GR at these frequencies (eg polarization) by directly detecting GWs from known systems with known orbital frequencies; perhaps observe directly GWs from a system with known orbital decay (double pulsar PSRJ0737-3039) – Observe bursts of GWs from cosmic strings or other exotic sources

8. LISA LISA Science - 2  Astrophysics – Study thousands of compact WD binaries, illuminate binary evolution, interaction, mass spectrum, … – Detect a handful of coalescences of BHs in range 10 5 -10 7 M , learn when first massive holes formed and what this had to do with galaxy formation. – Detect possibly dozens or more mergers of smaller BHs, learn how supermassive BHs formed, learn how galaxies formed from fragments. – Using coordinated optical or X-ray observations, identify systems containing BH mergers, measure cosmological acceleration, study dark energy. – Detect hundreds of EMRIs, determine spectrum of masses and spins of BHs in galaxies, study evolution of their central galactic bulges. – Look for a cosmological background of GWs, which might have arisen during the epoch of the electroweak phase transition. – Discover unexpected sources, possibly components of the dark matter.